Electromagnetic and optical trap systems play an important role in physics: such as Penning trap, Linear Ion (Paul) trap, magneto-optic trap, optical trap and diamagnetic trap. They are used to isolate matter which enables various high precision measurements to extract the intrinsic property of the matter and to perform various fundamental experiments in physics.
One such system that has been recently developed is a parallel dipole line (PDL) trap. A PDL trap enables trapping of a diamagnetic cylindrical object using transversely magnetized magnets that serve as the PDL system. The key feature of the trap is the “camelback magnetic potential” along the longitudinal axis that provides stable trapping. See, for example, Gunawan et al., “A parallel dipole line system,” Applied Physics Letters 106, pp. 062407-1-5 (February 2015) (hereinafter “Gunawan”); and U.S. Pat. Nos. 8,895,355, 9,093,377, and 9,236,293 all issued to Cao et al., entitled “Magnetic Trap for Cylindrical Diamagnetic Materials.”
The magnetic field profile (i.e., the camelback potential) along the longitudinal axis is fixed due to fixed length (L) and radius (a) and magnetization (M) of the magnet. However, for some applications it would be desirable to be able to control this magnetic field profile and potential.